Multi-constellation GNSS Integrity Check for Signal Manipulation Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
GNSS receivers in electric power delivery systems are vulnerable to signal manipulation, such as spoofing and jamming, which can lead to false time and position calculations, potentially causing improper control of the power system.
Innovation Solution
A system utilizing a time quality module that compares phase errors between signals from multiple GNSS constellations to detect manipulation, employing a phase detector, filter, and comparator to determine if a signal has been tampered with, and taking remedial actions like switching to a local or alternative time source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single GNSS constellation is used for time synchronization, then the system is simple to operate, but the system becomes vulnerable to signal manipulation and spoofing
Solution Approach 1:
The system segments the time synchronization function by using multiple independent GNSS constellations (GPS, GLONASS, Galileo, BeiDou) instead of relying on a single constellation. Each constellation operates as an independent time source, allowing the system to compare and validate time signals across different segments to detect manipulation.
Solution Approach 2:
The patent introduces an intermediary validation mechanism that compares phase errors between multiple GNSS constellations. This intermediary comparison process acts as a mediator to detect signal manipulation by identifying inconsistent phase error patterns that indicate spoofing or jamming attacks.
2Reliability
If multiple GNSS constellations are monitored and compared, then detection of signal manipulation is improved, but device complexity increases
Solution Approach 1:
The patent extracts the essential validation function by focusing solely on comparing phase errors between constellations, rather than implementing full signal processing for each constellation. This extraction approach simplifies the system by taking out only the critical comparison mechanism needed for detection while eliminating unnecessary complexity.
Solution Approach 2:
The system changes the monitoring parameter from full signal analysis to phase error comparison. By focusing on the specific parameter of phase error differences between constellations, the system achieves effective manipulation detection with reduced computational complexity and simpler device architecture.
3Measurement precision
If phase error comparison between multiple constellations is performed, then accuracy of manipulation detection is improved, but computational requirements increase
Solution Approach 1:
The patent employs a lightweight computational approach that uses simple phase error comparisons rather than complex signal analysis. This disposable-like simplicity in computation allows for rapid, energy-efficient detection by using basic mathematical operations that consume minimal computational resources while maintaining detection precision.
Solution Approach 2:
The system performs partial action by focusing only on the critical aspect of time signal validation (phase error comparison) rather than complete signal analysis. This partial approach achieves sufficient detection precision for security purposes while significantly reducing computational energy requirements compared to full signal processing.
Data Source
AI summary
The present application discloses detecting manipulation of GNSS signals using a second time source. If two or more GNSS constellation signals are being detected, the phase error between the GNSS constellation signals may be monitored. When the phase error drifts, then manipulation is determined. The integrity of a GNSS constellation signal may be monitored using an internal time source such as a crystal oscillator by monitoring a slope of the free running counter at the detected rising edges of a pulse-per-second signal from the GNSS constellation. If more than two GNSS constellations are monitored, a voting scheme may be used to determine the manipulated GNSS constellation.